My red boat was bad when I bought it. Compound wouldn't do a thing on mine.
I wet sanded and the quickest I found was to put on an old pair of swim trunks and have my son hold the garden hose above where I was sanding to keep the paper from clogging up. I also ended up wearing thick rubber gloves because my well water is darn cold.
Like Sam I also sanded up to 1500 and it polished out no problem.